EDICS

In each area, nine subject headings or chapters are available on EDICS: introduction, physics, design specs, types, good practice, examples, selection, dictionary, and self-test review.

The great amount of work required to develop EDICS has caused us to wonder if this is the most cost-effective way of achieving our goals.

We expect that the use of EDICS will lead to more knowledgeable study of texts, rather than to the abandonment of reading.

Low-level work on EDICS, which was funded by MIT's Project Athena, began in 1983-84, but the major part of EDICS development began in 1988 with a grant from the National Science Foundation.

In 1988, when we began the major effort to develop EDICS, many alternative hardware platforms were becoming available.

The MIT Athena Visual Computing Group, with whom we have been working throughout, is developing the Muse multimedia interface and is now transferring EDICS to its singlescreen system.

As an additional check to ensure that the [HbA.sub.1C] assay did not drift over the course of the DCCT and EDIC studies, four nondiabetic range studies were performed with the assumption that the true nondiabetic range should not change over time (1).

The values of [HbA.sub.1C] and selected characteristics of the nondiabetic populations over the course of the DCCT and EDIC are shown in Table 1.

Overall [HbA.sub.1C] values in the CHL vs the BHL differed slightly throughout the DCCT and for most of EDIC. However, despite efforts to sustain similar values, there were small differences between the CHL Diamat and the BHL, especially in the high [HbA.sub.1C] concentration range (>10% [HbA.sub.1C]), which increased beginning in 1995 until the CHL Diamat was replaced by the Tosoh 2.2 Plus in 2002.

The UKPDS used a Diamat assay (19) identical to that used for the greater part of the DCCT and EDIC.

By maintaining the same assay method over time at the BHL, we were able to monitor and achieve consistent [HbA.sub.1C] results throughout the DCCT and EDIC. Calibration to the BHL reference method provided stable results at the CHL, despite several changes in [HbA.sub.1C] methodology.

The Diamat with single-point calibration was suboptimal in maintaining consistent values between the CHL and BHL at higher [HbA.sub.1C] concentrations in both the DCCT and EDIC. The Tosoh A1c 2.2 Plus method also demonstrated somewhat greater variance with the BHL at the highest [HbA.sub.1C] concentrations, although to a lesser degree than the Diamat, possibly because of the two-point calibration of the 2.2 Plus.